Goldfish - Tail tips have turned black

[BlueSwan]

Otherwise healthy looking. But tail tips have turned black. Why is this happening?

[Slaphppy7]

Welcome to the AC.

Maybe that is just the natural coloring the GF will have after maturing?

[Boundava]

I agree, color may be changing as it grows/adjusts to new-better diet. How long have you had the goldfish?

[BlueSwan]

I agree, color may be changing as it grows/adjusts to new-better diet. How long have you had the goldfish?

This fish has been around for a few years now. May be 3-4 years.

[BlueSwan]

Welcome to the AC.

Maybe that is just the natural coloring the GF will have after maturing?

To put things in a different perspective, all my other fishes have died. Including rest of my gold fish. One by one. Not all together. None exhibited this type of color change. Many died from dropsy. This one is the last fish in the tank. I did not add any fishes fearing infection.

He seems alright. Just the blackening of tail... Water parameters are under control. No ammonia. pH is closer to 8.

[Slaphppy7]

How long has the tank been set up? Is it cycled?

What kind of test kit and water conditioner do you use?

[BlueSwan]

How long has the tank been set up? Is it cycled?

What kind of test kit and water conditioner do you use?

It's an 80 liter tank I have for around 8+ years now. Water conditioners are added during weekly / biweekly water changes only (25% change) 1. Anti-chlorine 2. Liquid that binds turbidity - blue green liquid that clear up within a day. I used in add aquarium salt, but stopped a few years ago without any adverse effect.

I test water using API kit for ammonia, pH, nitrites and nitrates. All parameters are within control. Like I mentioned previously the pH is closer to 8. I checked and the tap water has the same pH.

The only change I did about an year ago is start feeding them a spirulina extract flakes containing wheat, yeast, shrimp, krill paste etc..Kind of an omnivorous diet. Otherwise for all these years I was feeding them good quality freeze dried blood worms only.

I had guppies, betta fish, gold fishes, silver sharks...now only this 1 fish remains...

[Slaphppy7]

List the brand names of the conditioner and the "turbidity" stuff (which probably isn't needed).

Run the API liquid test, and post your results for AMM, NITRITEs, and NITRATES here...sounds like your water params are not good...or, disease has killed off your fish.

Did the fish all die in rapid succession, or gradually over time?

[BlueSwan]

These are brands available in India. The API test kit I have is based on color chart look ups. Not sure how I can post the readings...

[BlueSwan]

Did the fish all die in rapid succession, or gradually over time?

They didn't die in quick succession. Mostly one at a time. Guppies and betta died earlier in the year...the bigger ones started with the silver shark. He started becoming red..like having wounds on the body, black mouth. Then the gold fishes started to die. One by one. They become lethargic, staying at the bottom, gasping for air, red tails like ammonia poisoning but not really seen in test...last one had dropsy with scales like pine cones, black mouth, popped eyes...

The one that is alive is having this tail darkening. Not on fins or anywhere else. Just the tail tips. Otherwise he looks healthy. I still don't see the mock hunger behavior. He's not as active. But appears normal.